An Insight into Types of Bookbinding Glue
In the book industry today, adhesives are playing a significant role. Since its start, these binding adhesives have become the most demanding things for the book manufacturing industry. Due to the significant demand for these adhesives, there are over hundreds of bookbinding solutions that are available today. That being said, here are some different types of bookbinding adhesives that are used for binding books.
Starch and animal glues were some of the first types of adhesives used to attach envelopes or books. But these glues were gradually replaced by emulsion adhesives. And now, envelope glue and bookbinding glue is currently divided into three categories: water-based emulsions, hot melts, and reactive hot-melts.
Water-Based Emulsion
Water-based emulsion is produced from polyvinyl acetate (PVA), homopolymers or vinyl acetate-ethylene copolymers (VAE). However, most manufacturers generally prefer VAE because of its inherent flexibility. It is also worth it to note that these adhesives are mostly used in traditional binding processes.
When applying emulsion adhesives to the book, the water carrier provides incredible penetration into the paper. This penetration gives the necessary bond that holds the book together. The adhesives also have a semi-soft state that keeps the book spine more flexible.
Hot-Melt Bookbinding Adhesives
Hot-melt is considered one of the best bookbinding adhesives as it easily overcomes the problems of emulsion adhesives without affecting the characteristics of pull-strength and flexibility. The benefits of hot-melt adhesives is their high bonding speed, less waste material, and their relative affordability. They are most often based on ethylene-vinyl acetate (EVA) copolymers, styrene block copolymers (SBCs), and polyurethanes.
The flexibility of hot-melt bookbinding adhesives is of high value and they are relatively rigid to keep the book intact. However, if you are using a hot-melt adhesive, then it is important to keep the viscosity of the hot melt low as this gives the page a good pulling strength.
Ethylene Vinyl Acetate
EVAs are the application solution of hot-melt adhesives and they are made from a combination of solid thermoplastic copolymers, resins, and waxes that process the right viscosity when it is applied in bookbinding operations. EVA adhesives have strong properties, but one thing that sets them apart from other adhesives is their capacity to set quickly.
Reactive Polyurethane Hot-Melts
Reactive polyurethane hot-melt adhesives are a relatively new solution for bookbinding. Their introduction came in the 1980s for the furniture and automobile industry. They are considered as one of the strongest binding materials of the modern world. Due to a low melting point, polyurethane hot melt adhesives are solid prepolymers. They are similarly applied like conventional hot-melts but at lower temperatures. The main advantage of this adhesive is that it sets very quickly when it gets cool from melt form to solid.
Today, the solutions of bookbinding adhesives are far superior to those used long ago. However, due to their high demand, they are continuously improving to keep the bond between the pages of the book intact.
Author's Bio: The author in the above article gives detailed information about the bookbinding glue types that every book manufacturer needs to consider.